Blair H. Sheppard, Jon Hartwick, Paul R. Warshaw; The Theory of Reasoned Action: A Meta-Analysis of Past Research with Recommendations for Modifications and Future Research. J Consum Res 1988; 15 (3): 325-343. doi: 10.1086/209170
Two meta-analyses were conducted to Investigate the effectiveness of the Fishbein and Ajzen model in research to date. Strong overall evidence for the predictive utility of the model was found. Although numerous instances were identified in which researchers overstepped the boundary conditions initially proposed for the model, the predictive utility remained strong across conditions. However, three variables were proposed and found to moderate the effectiveness of the model. Suggested extensions to the model are discussed and general directions for future research are given.